Three-dimensional inverse dynamics of the forelimb of Beagles at a walk and trot

Abstract

OBJECTIVE To perform 3-D inverse dynamics analysis of the entire forelimb of healthy dogs during a walk and trot. ANIMALS 5 healthy adult Beagles. PROCEDURES The left forelimb of each dog was instrumented with 19 anatomic markers. X-ray fluoroscopy was used to optimize marker positions and perform scientific rotoscoping for 1 dog. Inverse dynamics were computed for each dog during a walk and trot on the basis of data obtained from an infrared motion-capture system and instrumented quad-band treadmill. Morphometric data were obtained from a virtual reconstruction of the left forelimb generated from a CT scan of the same dog that underwent scientific rotoscoping. RESULTS Segmental angles, torque, and power patterns were described for the scapula, humerus, ulna, and carpus segments in body frame. For the scapula and humerus, the kinematics and dynamics determined from fluoroscopy-based data varied substantially from those determined from the marker-based data. The dominant action of scapular rotation for forelimb kinematics was confirmed. Directional changes in the torque and power patterns for each segment were fairly consistent between the 2 gaits, but the amplitude of those changes was often greater at a trot than at a walk. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that control of the forelimb joints of dogs is similar for both a walk and trot. Rotation of the forelimb around its longitudinal axis and motion of the scapula should be reconsidered in the evaluation of musculoskeletal diseases, especially before and after treatment or rehabilitation.

A three-dimensional musculoskeletal model of the dog

“…excluding shoulder joint and scapular fulcrum, Nielsen et al, 2003;Burton, 2008;Burton 2011) and only one in three-dimensional analysis of the whole forelimb (Andrada et al, 2017). Note that only Niesen et al (2003) and Andrada et al (2017) reported on healthy dogs, and therefore the results of Burton, et al (2008) and Burton et al (2011) will not be further discussed here.…”

“…The Beagle model (BE-model) was built using computed tomography (CT) data of an adult Beagle (13.8 kg; Andrada et al, 2017). The resulting CT data set consisted of 3370 (spacing 0.33 mm) sections with a resolution of 512×512 pixels (spacing 0.279×0.279 mm).…”

“…For reconstruction, we use the segmentation software Amira® [amira] and the analysis software imageXd [imageXd] for automatic mesh generation. In addition, the segment masses (Andrada et al, 2017) and their moments of inertia were determined from the CT data (see Suppl. Mass/Inertia).…”

“…In order to drive the simulations, we used 3D-kinematic and kinetic data from a previous dog study (Andrada et al, 2017). Ten walking strides (joint angles and ground reaction forces from left fore-and hindlimbs) from the same individual from which we took the CT scan were used as the basis for our analysis.…”

“…For the sake of comparison, joint torques were also computed by using the 3D-Newton-Euler method (Eng and Winter, 1995;Winter, 2009), as already presented in Andrada et al, 2017. Here results are presented in the global frame to allow comparison with OpenSim (see supplementary document for more information).…”